Manie's Microcruiser

[Manie B]

Hi folks - thanks for the info.

It will be a round birdsmouth mast and it will be tapered.
Boom and yard will be rectangular, both tapered to the ends.

The reason why I am going this way is the popularity of round tapered masts as FREESTANDING. I have read of the good results that was achieved with square or rectangular masts that were supported with stays, but I am more comfortable with a round "stick" than a square "stick" freestanding.
The birdsmouth also has a greater contact area for glue than butt jointed.

We are working on much more data and I will publish all the figures and calculations when it all comes together.

The reason for the delay has been - what wood ??
The good news is Dries has located a local supplier that has SPRUCE at a good price. So know that we know we can get Spruce we can go ahead with final calculations.

So all round its good news and the project is back on track.
I have started experimenting with a jig to do the tapers and the results were excellent. Will post pics of that when it gets off the ground.

 

[Manie B]

Just a bit more info on what made me think in this direction

However, a ‘square’ section with rounded corners such as this would be unsuitable for any rig which uses mast hoops or parrel beads or a lug rig where the spar turns against the mast.

There have been several configurations used to increase the gluing areas across the width of built staves.

And several configurations which attempt to reduce wastage and at the same time produce large gluing surfaces.

Unfortunately while they will produce superb, strong masts they call for increasingly complex carpentry.

The ‘Birdsmouth’ technique developed by Noble-Masts in Bristol UK is perhaps one of the most successful of these techniques.

http://www.diy-wood-boat.com/Mast.html

There are several reasons why soft woods are the chosen type of timber used in the making of masts and spars.
The first and most obvious is that so any soft wood trees grow exceedingly tall and straight.
And because they have grown so tall and straight they have developed the ‘elasticity’ to withstand all that the elements can throw at them.
Soft woods are also more likely to be lighter in weight.
Sitka Spruce (Silver, Tideland or Menzies Spruce) has long been the top choice for mast builders.

here is a nice discussion on stiffness
http://www.woodworkforums.com/f169/gis-spars-109530/

To me a birdsmouth also looks "knitted" together, an interlocking unit that supports each other - if that makes sense
not just a couple of planks that were thrown together.
I also see the "other" attempts as justification to make the job easier, quicker, faster, and ultimately lazier.

One thing that I have learned the hard way, easy is not always better. Rather keep on slogging away, its worth it in the end.

here are some pics I got off the interenet
you can see where I am going with my "taper" jig, first cut in the "V" groove, turn around and then taper the opposite side. My side guides will be 50x50 steel tubing.

always exiting, always something on the go

 

[Manie B]

definately

But as weight and aerodynamics are more important at the top end of the mast then on the bottom and have a big impact on the boat's behavior and sailing capabilities I would adapt scantlings to that and taper the mast in both wall thickness and outher dimensions which means calculate the mast over whole length and not just the bottom.

and yes as well

taper the mast in both wall thickness and outher dimensions

I am working on 110 dia x 22mm thick for the bottom 2 meters and then the top 4 meters will taper down to 80 dia x 20mm thick.
:idea: so for "imperial" I am tapering a 4-1/2" mast down to 3-1/4" over the top 2/3 of the mast lenght. Total mast length is 20 ft.

Just to show my age
my country was still imperial when I started school (the dark ages)
so I only learned "metric" as a teen
the good thing is I can think in both
just goes to show my "split personality"
probably toooo much wine

 

[Fanie]

Actually Manie, we are in the dark ages now...

 

[hoytedow]

... and the beat goes on.

 

[Telein]

Nursing some infirmities today and stumbled upon your thread with subsequent link to the blog Manie. Read through all 683 posts in one sitting. Very impressive and wonderfully documented build.

As I prepare to start my first (of hopefully many) builds soon, this thread and your blog will serve to remind me of seeing through a job well done. Naysayers be damned, find them to be a jealous lot more to be pitied than scolded frankly.

Being the new guy in town I'll make mistakes but perseverance leads to progress. You have demonstrated that well and have my respect.

 

[masalai]

Hi Telein,
I hope you will commence your own thread to document progress on your build - I initially documented mine http://www.boatdesign.net/forums/boat-building/my-little-piece-peace-25962.html missed a bit near the end when I had my own website, (which I closed after launch), as I was not sure where I would go once I started cruising...

Most threads diverge from the build with regular questions diversions and generally good fun... - sort of like a conversation amongst friends where content covers almost everything in life, death- and beyond...

 

[Manie B]

Well folks - I am back home in the so-called civilization. The contract that I am working on takes us deep into the "country side" miles away from everywhere. I am contracting to a company that lays fibre optic cables all along the freeways connecting city to city all over South Africa.
As some of you may have picked up Wynand was down at the Vaaldam 2 weeks ago to do a COF and a Bouyancy cert for my mate on his new motorcat.

I am finally back in the garage working on my boat. It is still cold here but that "bitter" cold seems to be over.
I decided that I want to get my electrical system going first because that is going to be a priority for my "River ramble" that I am planning down the Vaal river. Sails will be of little help as I will motor all the way in any case.
So the "stereo" and lights is the most important for a weeks "camping" trip, not to forget the gas fridge
I am a "stew" man so no need for fancy cookers, the gas stove is all I need. A pot of rice with a nice beef or lamb stew is great with a bottle of red.

The smartest toy that I have ever had is my Iphone 4s. I will be shot down for this but the other phones simply cant compare. Check these apps out:-

Navionics = Australasia = the best charts and with Iphone features beyond imagination
Anchor alert = for dragging the anchor at night
Boat Tracker = marking waypoints and boat speed
Weather Track = GRIB files that are fantastic
Night Sky = all the stars as you point at them
Ship Finder = AIS in real time of the ships around you
Tides Plan 12 = tides and local info
Skype = talk to the missus
Compass = GPS from Apple

Now from what I have seen with the Raymarine products around here - nothing but nothing compares to the Navionics available to Apple Apps.
There is an App for anything in your imagination, and I mean anything.
The best of all is many are free and those that you have to buy are cheap.
I obviously know my systems well but the ease of operation makes the Raymarine stuff cumbersome and confusing. I just wish Apple would figure out a Radar system. Real time AIS is already available.
So the Navionics charts are 100% fantastic.

Hello summer - cant wait to go cruising again

 

[Manie B]

lousy photo but you get the idea

 

[Manie B]

Oh and the sound is waaay oout dude

 

[Fanie]

Hey Manie,

I was just going to comment that the okes on the Vaal is going to shoot at you, throw bottles at you and shout foul language for sailing on their water.

With that "sound system" at full volume and a sh3t experession on your face you should have no problems... they will think you are one of them !

How much did that yappi stuff rip you and what happens when you don't have tower reception ?

How about someone drops you off in Moz and pick you up in Richards Bay again ?

 

[Manie B]

Fanie the Navionics maps are on the phone permanently once down loaded and they function on GPS.
I have tested it - the maps and GPS definately works when there is no cell phone signal. So your "tower" signal is only for phone - SMS - and e-mail. Keep in mind we are connecting towers all over the country so we are regularly in areas where there is no signal.
I read a story of an Australian that went sailing all over the Pacific with his Iphone - that is where I got the leads to the good apps that work well with a proven history.
In South Africa you will pay up to ZAR 30k = US$ 4k for a Raymarine plotter and then the "charts" are very expensive extras that come on memory cards, also around 2 to 4 thousand Rands EACH.
My charts are Indian ocean and Australia and Micronesia =
Cape Town to Kuwait to Tokyo to Wellington and EVERYTHING IN BETWEEN
basically 15 deg West right around to 135 deg west and 45 deg south and 45 deg north - it is a vast area
ALL THIS FOR US$ 44 = ZAR 352.00 In my language that is for free.
The map of the Vaaldam is stunning

 

[Manie B]

oh and just before everybody thinks I lost the plot
here is my secret "weapon" on the go next project = my own power station

also in the pipe line is another 2 solar panels on a back "Arch"
the boat will have 4 x 100 amp batteries
sorry Wynand but we will have to recalculate the bulbkeel weight to compensate for the "interior" ballast

 

[Manie B]

fun generator

http://www.youtube.com/watch?v=NAFgnmZunnQ&feature=related

 

[Fanie]

Manie can the Ipad play through the car radio ?
It seems so and you have the maps on the external screen or is that a laptop ?
What outputs does the ipad have ?